1. Field of the Invention
The present invention relates to a backlight unit capable of preventing deterioration in image quality of a display image by controlling driving timing of a backlight in consideration of an operation speed of liquid crystal, a liquid crystal display device using the same, and a method for driving the backlight unit.
2. Discussion of the Related Art
With increasing adoption of information technology, demands for an image display device have been variously increased. Recently, a flat panel display device such as a Liquid Crystal Display (LCD) device, a Field Emission Display (FED) device, a Plasma Display Panel (PDP) device, or a Light Emitting Diode (LED) display device is mainly used.
An LCD device displays a desired image by adjusting transmission of light supplied from a backlight unit by a liquid crystal panel including a plurality of liquid crystal cells arranged in a matrix.
In the related art, fluorescent lamps have been used as the primary light sources for backlight units. However, recently, with increasing miniaturization, thinness and weight reduction of backlight units, a backlight unit using LEDs, which are advantageous in terms of power consumption, weight and luminance, as compared to fluorescent lamps, has been used.
Such a backlight unit adjusts the amount of driving current supplied to light sources such as LEDs so as to control the brightness of a backlight. In the related art, light with constant brightness may be supplied to a liquid crystal display device regardless of an image displayed on the liquid crystal display device. If the backlight is turned on or off regardless of a response speed of liquid crystal, a motion blurring phenomenon, in which a display image is blurred, occurs due to characteristics of liquid crystal having a low response speed.
In detail, in a liquid crystal display device, response speed is low due to characteristics such as inherent viscosity and elasticity of liquid crystal. In general, since the response speed of the liquid crystal is greater than a frame period (NTSC: 16.67 ms) of a moving display image, a frame transitions to a next frame before a voltage charged in a liquid crystal cell reaches a desired voltage. However, as described above, in the backlight unit of the related art, since the backlight is turned on or off regardless of the characteristics of the display image or the response speed of the liquid crystal, the image quality of the display image may be deteriorated.